i only have the dvd version 3.3, i cant play back up ps1 games on my ps2, but i have a ps1 emulator on my pc so i just play them on my pc, its called ePSXe, if you want it im sure you can find a place to download it on the web.

You need one original PS1 game, and a way to make the system think the tray is closed when it is actually open. (If you have a slim like me, you can either buy the magic keys or open the system and use some tape.

Put in the PS1 original and turn on the system. It should start to spin, and the PS2 starting animation will show up. As soon as it fades to black, remove your original and put in the PS1 backup.

Enjoy your game.

P.S. If you have an American PS2, you can only play backups of American games by this method.